Two hammer single rotor crusher with hydraulic operated feed chute



V. H. NIXON Aug. 24, 1965 TWO HAMMER SINGLE ROTOR CRUSHER WITH HYDRAULIC OPERATED FEED CHUTE 6 Sheets-Sheet 1 Filed May 24, 1963 (N X J m3? 4 5f M Aug. 24, 1965 v. H. NIXON TWO HAMMER SINGLE ROTOR CRUSHER WITH HYDRAULIC OPERATED FEED CHUTE 6 Sheets-Sheet 2 Filed May 24, 1963 QUE V. H. NIXON Aug. 24, 1965 TWO HAMMER SINGLE ROTOR CRUSHER WITH HYDRAULIC OPERATED FEED CHUTE 6 Sheets-Sheet 5 Filed May 24, 1963 Aug. 24, 1965 NIXON 3,202,367

V. H. TWO HAMMER SINGLE ROTOR CRUSHER WITH HYDRAULIC OPERATED FEED CHUTE Filed May 24, 1963 6 Sheets-Sheet 4 .l l ll llillilh Aug. 24, V. H. NIXON TWO HAMMER SINGLE ROTOR CRUSHER WITH HYDRAULIC OPERATED FEED CHUTE Filed May 24, 1963 6 Sheets-Sheet 5 V. H. NIXON Aug. 24, 1965 TWO HAMMER SINGLE ROTOR CRUSHER WITH HYDRAUL OPERATED FEED CHUTE 6 Sheets-Sheet 6 Filed May 24, 1963 United States Patent 3,202,367 TWO HAMMER SINGLE ROTOR CRUSHER WITH HYDRAULIC OPERATED FEED CHUTE Virgil H. Nixon, Joplin, Mo., assignor to Missouri-Rogers Corporation, Joplin, Mo., a corporation of Missouri Filed May 24, 1963, Ser. No. 282,989

9 Claims. '(Cl. 241-186) This invention relates to improvements in a rotary crusher and more specifically to an improved construction for a single rotor impacted type of crusher, such as shown in my prior application, Serial No. 837,053, filed August 31, 1959, now abandoned, entitled Single Rotor Crusher With Breaker Bars, of which this application is a continuation-in-part.

It is an object of this invention to provide an improved single rotor machine with double the capacity, or output, produced by comparable machines.

Another object of this invention is to provide a machine of the above type with improved mountings for locating the breaker bars in the breaker bar grating.

Another object of this invention is to provide a machine of this kind with an improvement capable of clearing the machine for continued operation by eliminating bridging and without risk of injury to operating personnel or damage to the machine.

According to this invention, the crusher comprises a housing with side, back and top walls enclosing the rotor and a space above the rotor which can be termed a reducing chamber. A front wall of the housing forms an opening for charging the machine with rock. The bottom of the housing is open to provide for discharging the crushed rock. Located between the charging and the discharging openings is a rotor journalled in bearings external of each side wall. The rotor carries two rows of hammers on its periphery spaced 180 apart. The rotor and hammers extend from one side wall to the other inside the housing. A breaker bar grating extends vertically between the side walls of the housing and has a plurality of breaker bars forming the grating which ex-' tend horizontally between the side walls of the housing in parallel vertically spaced relationship. The breaker bar grating is spaced from the top and back wall of the housing and is in part coextensive with these walls, there being a space between the breaker bar grating and the back wall through which fragments of the crushed rock may pass to the discharging opening. The breaker bars in the upper portions of the housing are in relatively fixed positions and are conveniently mounted in openings cut in the side walls through which the bar ends project, the bars then being held against endwise displacement, as by collars on the bar ends or by elongated plates which are fastened to the outer surface of the side walls over the projecting ends of the breaker bars.

The material fed to the rotor of the crusher is intro duced through the charging opening and guided to the rotor by a feed chute inclined downwardly and inwardly to the rotor with its lower end disposed to one side of a vertical plane through the rotor axis at a level about that of a horizontal plane through the rotor axis. It has been discovered that the infeed of rock at this location on the rotor causes an impact by the hammers in which fragments are propelled upwardly through the reducing chamher to a region on the side of the vertical plane through the rotor axis opposite said chute. This flight path of the fragments is intercepted by the breaker bar grating, and the initial crushing obtained by this first impact is extremely effective.

At the lower edge of the breaker bar grating are adjustable breaker bars, one of which can be termed a final size control breaker bar. Its function is to determine the final maximum size of the fragments and for this purpose is normally more closely spaced to the outside of the hammer circle than any of the other breaker bars. Because it is more closely spaced, a secondary crushing action can take place at the location between this control bar and the hammers should larger fragments than the maximum permissible size reach this zone of action. These adjustable breaker bars, including the control bar, are located on the side of the rotor opposite the feed chute.

For some uses, the lower of the adjustable bars can be the final size control bar positioned parallel with the rotor axis, closer to the hammer circle than any others, and located vertically between a horizontal plane containing the rotor axis and the highest part of the hammer circle above that plane, in which position, primary crushing is carried out.

When still further crushing is required, provision is made in the machine to receive still another breaker bar. Holes in the side walls provide for insertion of this breaker bar parallel to and below the adjustable bars and still closer to the hammer circle, but less than half of the hammer circle away from the end of the feed chute.

In mounting the adjustable bars, horizontal slots are cut through the side walls to accommodate the bar ends, and U-shaped brackets are fastened to the side walls so that the legs of a bracket extend rearwardly above and below the adjacent slot. The end of a breaker bar is then held between a pair of support blocks slidably recessed to embrace the end of the bar, and the blocks are slidably mounted between the bracket legs.

Each bar supporting block is backed up by a set of shims, the front set being held by a lock bolt threaded through the front of the bracket and the back set of shims being held by a plate, or block, hinged on a pivot pin in the back of the bracket and extending between the legs thereof. This back plate, or block, is releasably secured by a shear pin, but can swing back when the shear pin breaks, as might occur during a jam. These breaker bars, that are adjustable, can be moved toward, orfaway, from the rotor by adding or removing shims. This construction is preferred since there is less likelihood of broken parts flying off the machine in case of a jam. In,

blocks to the front portion of the bracket Where an in-' turned lip provided thereon may be secured by the lock bolt.

It has been discovered that a machine, such as the one above briefly described having only two rows of hammers spaced 180 apart on the rotor, produces more than double the output of a four hammer rotor with four rows of hammers spaced only apart on the rotor, where both rotors are operated within a normal speed range. The normal speed range in machines of this kind is in the order of 500 r.p.m. Thus, the use of 'a two hammer rotor in the crusher described is regarded as an important feature of this invention. 7

Another important feature of this invention resides in a further modification of the machine which also results in increased production. This particular feature is an hydraulic operated feed chute, or plate, to eliminate the effect of bridging which occurs within the housing under certain unfavorable conditions and blocks the feeding of rock to the rotor. During quarrying, the rock is broken up by blasting. A'certain percentage of the broken rock will be in large chunks. Often one of these large chunks will become wedged on the feed chute when loaded in the crusher and, when wedged, is held up out of the an appreciable length of time for it may be several minutes or so after the power is shut oif that the rotor comes to a halt. It is then safe to attempt to remove the large chunk, which hasbecome wedged, by hoist, shovel or winch truck. If this fails, the chunk may be blasted out by a charge of dynamite. When the machine is cleared, it is then safe to start it up, but it may require as much as several minutes before the rotor comes up to speed. Since the delay entailed in clearing the machine represents a loss in production, it is costly. To avoid this loss of time, this machine has' movably connected wall members in the housing which may be hydraulically moved to expand,or contract, the size of the charging opening and reducing chamber. Operation of this hydraulic mechanism will allow the rock to fall down into contact with the rotor hammers where it will be shattered and crushed immediately. This is all done without a shutdown, or stopping, of the rotor so that the period in which the crusher is out of production is only momentary and output of the machine remains near peak production.

This bridging condition, above described, may not be caused by a single large chunk alone, but may be caused by two, three, or more, smaller pieces which will lodge together in an arch, keyed up and bridging over the path of travel of the rotor hammers. The results are the same as with the large chunk, however. The hydraulic mechanism can clear the machine of this kind of bridging in the same manner. In the preferred form of this invention, hydraulic power moves the chute and the piece, or pieces, forming the bridge, lose support and fall into the path of the rotor hammers. The pump for supplying the hdyraulic power to operate the feed chute may be manually, or motor driven.

Other objects and advantages of this invention will appear from the following detailed description of the invention which is in such full, clear, and exact terms as to enable any persons skilled in the art to make and use the same when taken with the accompanying drawings, forming a part thereof and in which:

FIG. 1 is a side elevation of a crusher embodying this invention;

FIG. 2 is a front elevation of the crusher shown in FIG. 1;

FIG. 3 is a vertical section through the crusher taken on the line 3-3 of FIG. 2 looking in the direction of the arrows;

FIG. 4 is an exploded view in perspective of the means for holding an adjustable breaker bar;

FIG. 5 is an exploded view in perspective of the rotor;

FIG. 6 is an exploded view in perspective of the hammer locking wedge elements used in the rotor shown in FIG. 5;

FIG. 7 is a perspective view of a modified form of machine shown in elevation;

FIG. 8 is a fragmentary perspective view of the modified machine in elevation showing the charging chute in lowered position;

FIG. 9 is a side elevational view in section of the modified machine; and

FIG. 10 is a schematic view of the operating mechanism for the charging chute.

Referring to the drawings, the main base of the machine comprises a pair of I-beams ll extending along opposite sides of the housing and a pair of transverse beams '3 extending across the front and back of the machine.

Lower side plates 5 are mounted immediately inside of the longitudinal base members 1 and are secured thereto by triangular gusset plates 7 fastened to horizontal plates 9, which rest upon the side base members 1. The discharge chamber at the lower end of the crusher is defined by a pair of inclined front and back plates 11 which span the space between the side plates 5 and are secured thereto. The rotor bearings 13 are suitably supported upon the longitudinal base members 1, as by pillow blocks 15.

The side walls of the housing are further defined by intermediate plates '17 resting upon the lower plates 5 and secured by strips 6. Upper plates 19 secured by strips 8 complete the side walls. A back wall 21 fastened be tween the side wall sections 17 extends upwardly from the back discharge plate 11, and top-forming walls 23 fastened between side sections 19 extend across the back upper portion of the housing. The front 25 of the housing is opened for entry of the rock, and an open front hood 27 is mounted on the upper front portion of the housing so as to provide a larger feed entrance. It will be noted in FIG. 2 that the thickness of the side wall plates diminishes in the upward direction, hence the side wall structure formed from a multiplicity of side plates is advantageous in achieving an economical construction consistent with the strength requirements of a crusher, wherein the greater wear is at the lower portion adjacent the rotor. Also, the several side sections permit adjustment in the height of the machine, as by replacement of side sections at the upper part of the machine. Chains 29 may be hung from the top of the hood 27, as illustrated in FIG. 2,'the rock being fed between the lower ends of the chains and the top of aninclined feed plate, or chute, 31. The chains permit large rock to enter the machine while permitting the smaller rocks from being thrown outwardly during the crushing operation.

The location of the feed plate 31 with respect to the rotor and the primary breaker bars is important. The top of the feed plate may be from thirty to forty-five inches above the axis' of the rotor, depending upon the size of the crusher, and the plate inclinesdownwardly close to the periphery of the rotor at an angle such as to intersect with a point slightly above the axis of the rotor. The horizontal distance between the axis of the rotor and the front edge of the feed plate might be three to five feet, depending upon the size of the crusher. Also, the space below the inner edge of the feed plate may be closed olf with a plate 33 extending between the side walls of the housing, the plate 33 extending from the inner edge of the feed plate 31 forwardly and downwardly at approximately a right angle with respect to the feed plate and terminating adjacent the upper edge of the front discharge plate 11.

The rock is thrown by the rotor against horizontal breaker bars mounted in spaced parallel relationship to span the side walls of the housing adjacent the top and back walls of the machine but in spaced relationship from the walls, thereby to provide a chute for the small product to fall into the discharge outlet. The upper breaker bars 35 are fixed within the machine at predetermined positions. In accordance with this invention, the breaker bars 35 are rod-like members which extend through slightly larger openings in the side plates 17 and 19. The breaker bars are of a length such that they project into the side walls and are thereby held directly by the side walls, but the portion of a bar between the side walls may support a hardened wear sleeve. End closure plates 37 are shown to be bolted or otherwise fastenedto the outer surfaces of the side walls to prevent endwise displacement of the breaker bars.

It will be noted that the upper fixed breaker bars 35 extend downwardly to a line opposite the upper front portion of the feed plate 31. A pair of relatively adjustable breaker bars 39 with wear sleeves 36 are then mounted in the space horizontally opposite from the feed plate 31, and these breaker bars 39 are also mounted so as to 39. In the condition shown in the drawing,-the lower one of bars 39, being closer to the path of the rotor,

controls the maximum size of product which can pass from the explosion chamber to the discharge chamber; it being noted in this connection that there is greater clearance between the lower bar 39 and most of the periph eral surface of the rotor than there is between adjacent breaker bars. When a substantial amount of large size product is desired, the lower one of bars 39 may be omitted, thereby to cause the upper one of bars 39 to become the control bar and provide clearance for the passage into the discharge chamber of larger pieces of rock.

The manner of supporting the adjustable breaker bars is one of the features of this invention. A generally horizontally elongate slot 41 is cut in each side plate 17 for each breaker bar 39, and a U-shaped stirrup bracket is then fastened to the side wall so that the legs 43 of the stirrup, or bracket, project rearwardly on opposite sides of the slot. The bracket opens in the rearward direction and is closed by a front plate 45. The breaker bar 39 is then held within a bearing-like block, or blocks, 47 which are horizontally movable between the legs 43 of the stirrup. The blocks 47, in turn, are adjustable horizontally by means of shims 49 backing up the breaker-supporting blocks both at the front and back thereof. The front set of shims is held by a lock bolt 50 which extends through a threaded opening 51 in the front closure wall 41 of the bracket, whereas the back set of shims is held by a pivotally supported shear pin block 53. It will be noted that the back portions 55 of the stirrup bracket project outwardly from the side wall of the housing so as to support a pivot pin 57 in spaced relationship from the side wall. The shear pin block then extends inwardly from the pivot pin 57 at right angles to the side wall so as to hold the back shim 47 and is itself secured by an inner shear pin 59. A keeper plate 61 may hold both the pivot pin and shear pin within the stirrup bracket. Finally, a cover plate 63 is also secured upon the pivot pin 57 to extend forwardly over the shims 49 and supporting blocks 47. An inwardly directed flange 65 extends from the front of the cover plate within the stirrup bracket and is secured by the lock bolt 50, there being a suitably large aperture 67 in the flange 65 through which the lock bolt may project.

The advantage with this arrangement is that it not only permits adjustment of the breaker bar positions by removing or adding shims, but also protects the apparatus by releasing the breaker bar through rupture of the shear pin and further encloses the flying parts so that bystanders or adjacent equipment will not be injured. The forces developed when a shear pin breaks are so great that the parts tend to fly outwardly at considerable velocity and could injure, or damage, personnel or equipment nearby,

if not secured to the crusher or suitably enclosed.

The crusher of this invention further includes another breaker bar 71 mounted slightly below the horizontal axis of the rotor, which breaker bar 71 is removable, so as to permit the crusher to be used for both primary and secondary crushing. The bar 71 is removed during primary crushing and is inserted for secondary crushing, or reduction, of the rock to relatively small size. Deflector breaker bars 73 may be located below the bar 71 adjacent the periphery of the rotor so as to screen out material and prevent rock from being carried back around to the feed entrance of the machine. The breaker bar 71 is secured in the same fashion as the breaker bars 35,

there being an end plate 75 which is bolted to the sidewall 5 to prevent endwise displacement, the bar otherwise being held by projecting into or through close fitting openings in the side wall plates 5.

The rotor of this crusher is positioned so as to project upwardly above a line extending generaly horizontally between the lower part of the feed plate 31 and the lower adjustable breaker bar 39. As will be apparent from an inspection of FIG. 3, the reducing chamber, referred to here as an explosion chamber, is the space within the housing above the hammer circle. breaker bar 71 is present, or not, the crushing takes place Whether within less than half the circular path of the hammer circle. The first impact between rock and hammer would be at a point above the surface of chute 31. The final impact between hammer and rock would take place at lower breaker bar 39, or at breaker bar 71, which are spaced less than half a circle away from the lower edge of chute 31. Accordingly, the crushing is performed by only one hammer at a time. To some extent operating torque is more uniform. Wide fluctuation in rotor speed is avoided and impact speed maintained.

The rotor shaft 81 is supported in the bearings 13 and the rotor 83 is a solid casting which is secured on and keyed to the shaft. Rotor rings 85 may be attached to the ends of the rotor itself. Although the rotor is a solid casting with weight-reducing holes 84, it is not truly cylindric, but rather has a shape that would be produced if a cylinder were sliced diametrically and the two halves slipped on the diameter so as to provide radial faces or shoulders 87 on opposite sides. The hammers 89 are then secured against the shoulders 87.

Each hammer is an elongate narrow plate of hard wearing material, but the inner edge thereof is specially shaped to lock within a slot 90 extendin lengthwise across the rotor in front of a shoulder 87. A bevel 91 is formed along the inner front face of the hammer for cooperation with certain wedge members fitting within the front part of slot 90. The inner back portion of the hammer has a rearwardly projecting lip 93, which is locked or received within a dovetail portion 94 in the back part of the hammer supporting slot 90.

The Wedge members force the lip rearwardly into the rotor so as to lock it against radial displacement. In addition, bolts 95 may extend through the hammer and rotor so as to provide a further means of securing the hammer, but the wedge and lip lock is the primary means of holding the hammer within the rotor.

The wedge elements are accommodated within a dove tail groove 97 extending across the front of slot 90 and the rotor end rings are also cut away opposite the ends of this slot so as to permit adjustment of the wedge action. A pair of elongate tapering Wedge elements 99 telescope over the draw rod 101, and each wedge element is shaped so as to have larger cross-sections in the direction outwardly or endwise of the rotor. When the wedge elements 99 are then drawn toward one another on the draw rod, they wedge the hammer firmly within the rotor. One end of the draw rod 101 is threaded to receive a nut 103 by means of which the wedges are drawn inwardly. It is desirable, however, to provide a locking arrangement for the nut 103, and such a lock is conveniently provided by slitting the threaded end 105 of the draw rod and by providing a tapped hole in the end of the rod for accommodating a pipe plug 107 (FIG. 6). After adjustment of the nut 103, the pipe plug 107 is screwed in to expand the bifurcated ends of the rod and lock the nut 103 securely thereon against loosening under the forces of vibration.

In operation, chunks of rock are fed through the charging opening 25 down the chute, or plate, 31. The end of this plate is disposed above a horizontal plane through the axis of the rotor 83 and to one side of a vertical plane through the rotor axis. In order to obtain the desired feeding action for best performance of the hammers 88,

the end of the chute 31 is disposed below the top of the hammer circle. In other words, a diameter through the rotor axis parallel to the inc-lined surf-ace of the chute lies below the chute upper surface. The lower breaker bar of the grating, where final crushing occurs, is spaced less than half a hammer circle from the chute. This relationship with the rotor and in combination with hammers on the rotor spaced apart, more than doubles the produc tion rate obtained from the same machine with twice the number of hammers and driven in the same range of 7 r In the modified form of the invention disclosed in FIGS. 7 through 10, the side wall members enclosing the reducing chamber and defining the charging opening are relatively movable to expand and contract. In the form shown, the machine is provided with a movable (tiltable) feed plate, or chute. Otherwise, the construction of the machine is the same as above described. This description will accordingly be limited to the form of the plate, or chute, its special mounting, and its operation. Referring now to FIGS. 7 and 9 particularly, opposite side wall members 17 of the housing are apertured at 115 to receive the ends of elongated hinge pins 116. Both ends of binge pins 116 project to the outside of the opposite side walls. Both ends are secured in the same manner by suitable washers and cotter keys 117 and 118. The feed chute, or plate, 31' is secured to a framework comprising segment-shaped sealing plate members 120 and 121 .at its opposite edges. Between these plates 120 and 121 are transverse members 123 and 124 with their opposite ends welded to the sealing plates 120 and 121. A pair of apertured bearing blocks 126 are journalled on the hinge pins 116 and in turn welded between the bar member 123 and the plates 120 and 121 at opposite edges of the feed chute 31. A pair of spaced apart brackets 128, one of which is shown in FIG. 9, are welded in opposite corners between the cross bar 124 and to each of the plates 120 and 121. Brackets 128 are apertured to receive elongated pins 130. On the opposite side of the bar 124 from the brackets 128 are a pair of spaced webs 132, one of which is shown in FIG. 9. Webs 132 are welded in position at opposite edges of the chute 31 and apertured to receivebars 136 which have ends projecting beyond opposite edges of the chute, as shown for example in FIGS. 7 and 8.

Opposite sides of the machine are provided with identical hooks for engagement with the projecting ends of bars 136. Since both the hooks and the operating members for the hooks and their mounting are the same, only one will be described. Thus, turning to FIGS. 7 and 8, a latch 140 with a hook end 141 in which the end of the baris seated is pivotally mounted about pivot 143 which is a stud projecting through an aperture in bracket 145, a suitable aperture'in latch 1'41), and threaded into the side wall 17. An arm 147 on the latch 140 is provided for rocking the latch to and from a released position with respect to the ends of bars 136. A stop 14% limits the motion in one direction. Tie rod 150 is secured to the arm 147 by a suitable pin type clevis 151 and extends to a similar clevis 154 pivotally attached to the end of arm 155. A rock shaft 159 mounted in spaced bearings 160 on the top wall of the machine carries the rock arms 155. Both arms 155 and operating handle 165 are secured to the rock shaft 159 so that movement of the hand-1e 165 in opposite directions engages and disengages the latches 140 with the ends of the bars 136.

- Sealing plates 121) and 121 are secured to the edges of plate'31' to form a chute within the inner walls 17 of the machine which can swing in and out, as feed plate 31 hinges about the hinge pins 116. The movement of the plate 31' is under the control of a pair of double acting hydraulic jacks 175 and 176. The lower ends of these jacks are hinged to pairs of spaced brackets 182 and 184 welded to the cross frame member 3. The piston rods 185 and 187 of each jack are pivoted on rods 130.

Jacks 175 and 176, as shown in FIG. 10, receivetheir hydraulic power through identical fluid connections. For example, there are provided a pair of fluid connections 188 and 191) at the upper end of each jack and a pair of fluid connections 191 and 193 at the lower end of each jack. Hydraulic line 194 interconnects the connections 188 and 190, and hydraulic line 196 interconnects the two connections 191 and 193. The lines 194 and 196 in turn are supplied with hydraulic fluid from'a four-way valve of standard construction 198 provided with a handle 199. A line 201) is provided to connect from a source of pressure in the pump 202 with the valve 198. An exhaust line 294 connects the four-way valve 198 with the sump in the pump 202. A handle 205 on the pump is rockable to operate the pump and supply pressure through the line 200 to the four-way valve 198. With the handle 199 in the position shown in FIG. 10, pressure is supplied to the hydraulic line 194 while line 196 is connectedwith the sump in the pump through the line 204. In the reverse position of the handle 199, line 196 is connected with the source of pressure in the pump and line 194 is connected by way of line 204 with the sump in the pump.

Assuming that the feed plate 31 is in the latched po sition and the machine is operating, should a bridging condition be encountered which stops the feeding of rock to the rotor, the operator mounts to the top of the machine where he is in a safe position from any flying rocks. From this position, all of the controls are accessible. To clear the bridge, the four-way valve is reversed by turn: ing the handle 199 180 from the position shown to supply pressure .to the hydraulic line 196. Pump handle 205 is operated to lift the feed chute 31' at its outer end and raised to the bars 136 from their position within the hooks 141. The operator then seizes lever and rocks it to the right or toward the front of the machine disengaging the latches. Valve 199 is then reversed in position to supply the pressure to hydraulic line 194 and handle 205 oscillated to supply pressure to the upper ends of the hydraulic jacks and 176 to draw the feed plate 31' down to the position shown in FIG. '8 Where the bar 136 rests upon the support 210 of the framework 213 carrying the apron 215. The tilting of the feed plate 31, into the position shown in FIG. 8, usually clears the bridge so that the machine is ready to accept a charge in the normal way. As the feed plate 31' is being lowered, the support of the rock, or rocks, which have become wedged in stationary position, is Withdrawn. the rotor and are crushed into fragments.

The fact that the bridge has been cleared is readily detectable 'by the operator on top of the machine. The feed plate is then returned to its inclined position, as shown in FIG. 9, by reversing the position of the handle 199 to supply pressure to the hydraulic line 196. Pump, handle 205 is operated supplying pressure to the lower ends of the hydaulic cylinders 175 and 176 to raise the feed plate to its upper limit of movement. Resistance to the action of the pump at this point will indicate to the operator that the plate has assumed its uppermost position. At this point, handle 165 is moved to the left toward the rear of the machine so as to drop the latches 140 into latched position with the ends of the bar 136. Preferably, the operator then reverses the position of handle 199 to supply line 194 with hydraulic pressure and lower the bar 136 into the hooks 141.

Raising the feed plate up to unlatch it, and then lowering it, is usually suflicient to clear the machine of any bridged rock, and this operation can be safely performed with the rotor operating at rated speed because the operator is in a safe position in which he is not liable to be hit by flying fragments from the rotor. However, if one cycle of operation does not clear the bridging from the machine, the sequence of operations can be performed several times by leaving the latches disengaged. Sooner or later this clears the bridging and the machine begins to operate in a normal fashion.

Changes in and modifications of the construction described may be made without departing from the spirit 1. In an impact crusher having a housing with an inlet.

opening in the upper portion thereof and a discharge opening at the bottom thereof, a single rotor journalled above said discharge opening and having hammers arranged thereon with axially extending faces exposed on one side Consequently, the rocks fall by gravity into.

facing the direction of rotation of said rotor, and peripheral surfaces thereon constituting the maximum radius of said rotor and defining a hammer circle during rotation; side walls for said housing at opposite ends of said rotor; and a reducing chamber which includes said side walls, a feed chute located between the said side walls with its discharge end disposed adjacent said hammer circle and a breaker bar grating located between said side walls and extending from above the hammer bar circle to a point closely adjacent the hammer bar circle and spaced from the edge of said feed chute in the direction of rotation of said rotor, the improvement which comprises,

(1) said rotor being located so that only the upper portion of the hammer circle is disposed in said reducing chamber, and

(2) said hammers being so spaced circumferentially of said rotor so that only one hammer at a time travelling in the hammer circle passes through said reducing chamber.

2. In an impact crusher having a housing with an inlet opening in the upper portion thereof, a discharge opening at the bottom thereof, a rotor located between said discharge opening and said inlet opening, hammers mounted on said rotor, and a reducing chamber in said housing located between said inlet opening and said rotor, the improvement comprising,

(1) a plurality of upright wall members and a feed chute member connected at their edges to form a portion of said housing enclosing said reducing chamber, said feed chute member extending between spaced wall members from adjacent said inlet opening downwardly and inwardly to adjacent said rotor,

(2) a hinge connecting one of said members with another, and

(3) means for moving said one of said members on said hinge in a direction outwardly of said reducing chamber to free material wedged against said one of said members and other of said members, said feed chute being a planar member hinged at its lower discharge end to each of said wall members and said feed chute includes sealing plates extending along opposite sides of said chute slidably engaging with the inner surface of said upright wall members.

3. In an impact crusher having a housing with an inlet opening in the upper portion thereof, a discharge opening at the bottom thereof, a rotor located between said discharge opening and said inlet opening, hammers mounted on said rotor, and a reducing chamber in said housing located between said inlet opening and said rotor, the improvement comprising,

(l) a plurality of upright wall members and a feed chute member connected at their edges to form a portion of said housing enclosing said reducing chamber, said feed chute member extending between spaced wall members from adjacent said inlet opening downwardly and inwardly to adjacent said rotor,

(2) a hinge connecting one of said members with another,

(3) means for moving said one of said members on said hinge in a direction outwardly of said reducing chamber to free material wedged against said one of said members and other of said members,

(4) a latch mechanism engageable with said chute member for holding said chute member and said wall members in fixed relative position with respect to one another, and

(5) means for releasing said latch mechanism.

4. In an impact crusher having a housing including top, back, and side walls, a discharge opening at the bottom of said housing, a front wall for said housing spaced from said top wall to define a charging opening, a rotor carrying crushing hammers journalled for rotation in said housing and located between said discharge opening and said charging opening, and an inclined feed chute extending downwardly and inwardly with respect to said front wall, the improvement comprising,

(1) a hinge mounting for said feed chute supporting said chute for swinging inwardly and outwardly with respect to said housing,

(2) latch means engageable with said feed chute for supporting said feed chute in a fixed position with respect to said housing and releasable therefrom,

(3) jack means connected to swing said feed chute with respect to said housing when said. latch means is released, and

(4) operating means for said latch means and said jack means located on the upper side of the top wall of said housing.

5. In an impact crusher having a housing including top, back, and side walls, a discharge opening at the bottom of said housing, a front wall for said housing s aced from said top wall to define a charging opening, a rotor carrying crushing hammers and journalled for rotation in said housing and located between said discharge opening and said charging opening, and an inclined feed chute extending downwardly and inwardly of said housing to said front wall, the improvement comprising,

(1) a hinge mounting for the inner end of said feed chute supporting said chute for swinging inwardly and outwardly with respect to said housing,

(2) latch means mounted on said housing for movement into or out of connection with the swinging end of said feed chute for supporting or releasing said feed chute with respect to said housing,

(3) a curved apron mounted on a bracket attached to said housing to enclose the swinging: end of said feed chute,

(4) stop means on said feed chute engageable With the bracket mounting said apron and with said housing to limit swinging movement of said feed chute,

(5) jack means connected to swing said feed chute with respect to said housing when said latch means is disconnected from the end of said chute, and

(6) control means for said latch means and said jack means located on the upper side of the top wall of said housing.

6. The crusher in claim 5 in which said operating means includes a source of hydraulic pressure and line connections from said source to operate said jacks, and said controls include a selector valve in said line connections and a rockably mounted handle with linkage connected to operate said latch means. 7

7. In a crusher of the type wherein input material is thrown about and subjected to impact while in flight to disintegrate it, the combination of, rotor carrying hammers arranged to strike and throw input material, means for confining the flight of such material from said hammers, said confining means including:

(a) opposite side walls at the ends of the rotor and extending substantially thereabove,

(b) a series of breaker bars mounted between said side walls, above and substantially spaced from said rotor,

(c) a front wall substantially spaced from said rotor and connecting said side walls,

(d) a movable wall section normally inclining downwardly from said front wall toward said rotor and bridging the space therebtween,

said confining means having an infeed opening above said movable wall section, and externally manipulable means for moving said movable wall section to vary the distance between it and parts (b) and (c) of said confining means.

8. The combination of claim 7 wherein said movable wall section is provided with a pivot axis adjacent said rotor.

9. The combination of claim 7 wherein said means for' moving said movable section is fluid-pressure oper- 2,463,223

ated. 2,618,438

References Cited by the Examiner 2,767,928

v UNITED STATES PATENTS 5 32 1,439,781 12/22 Williams 241-189 9119 1,864,973 6/32 Buchanan 241189 Verch 241189 X Chrystal 241189 X Moore 241186 Hanse et a1. 241-186 Berling 241 186 Andreas 241-189 J. SPENCER OVERHOLSER, Primary Examiner. 

1. IN AN IMPACT CRUSHER HAVING A HOUSING WITH AN INLET OPENING IN THE UPPER PORTION THEREOF AND A DISCHARGE OPENING AT THE BOTTOM THEREOF, A SINGLE ROTOR JOURNALLED ABOVE SAID DISCHARGE OPENING AND HAVING HAMMERS ARRANGED THEREON WITH AXIALLY EXTENDING FACES EXPOSED ON ONE SIDE FACING THE DIRECTION OF ROTATION OF SAID ROTOR, AND PERIPHERAL SURFACES THEREON CONSTITUTING THE MAXIMUM RADIUS OF SAID ROTOR AND DEFINING A HAMMER CIRCLE DURING ROTATION; SIDE WALLS FOR SAID HOUSING AT OPPOSITE ENDS OF SAID ROTOR; AND A REDUCING CHAMBER WHICH INCLUDES SAID SIDE WALLS, A FEED CHUTE LOCATED BETWEEN THE SAID SIDE WALLS WITH ITS DISCHARGE END DISPOSED ADJACENT SAID HAMMER CIRCLE AND A BREAKER BAR GRATING LOCATED BETWEEN SAID SIDE WALLS AND EXTENDING FROM ABOVE THE HAMMER BAR CIRCLE TO A POINT CLOSELY ADJACENT THE HAMMER BAR CIRCLE AND SPACED FROM THE EDGE OF SAID FEED CHUTE IN THE DIRECTION OF ROTATION OF SAID ROTOR, THE IMPROVEMENT WHICH COMPRISES, (1) SAID ROTOR BEING LOCATED SO THAT ONLY THE UPPER PORTION OF THE HAMMER CIRCLE IS DISPOSED IN SAID REDUCING CHAMBER, AND (2) SAID HAMMERS BEING SO SPACED CIRCUMFERENTIALLY OF SAID ROTOR SO THAT ONLY ONE HAMMER AT A TIME TRAVELLING IN THE HAMMER CIRCLE PASES THROUGH SAID REDUCING CHAMBER. 